Fifty-seventh annual meeting of the American association of physicists in medicine
WE-G-207-01: Motion-Compensated Iterative Reconstruction of Coronary Artery Based On 3D/2D Deformable Image Registration
The 3D reconstruction of coronary artery from x-ray angiograms rotationally acquired on c-arm is a challenging task because of the vessel motion. While ECG gated reconstruction have shown promising results, residual vessel motion exists because of imperfect gating or irregular motion, and affects the reconstruction quality. The purpose of this work is to propose and validate a new motion-compensated reconstruction method to reduce the effect of residual vessel motion.
The proposed method consisted of three main steps. First, a subset of angiograms were selected using nearest-neighbor ECG gating and used to perform the initial reconstruction based on a L1 and total variation regularized iterative reconstruction method. Due to the residual vessel motion, the initial Result exhibited motion artifacts which hindered its clinical usage. Next, a novel 3D/2D registration method was proposed to estimate the vessel motion between the initial reconstruction and the vessel morphology corresponding to each angiogram. Finally, a regularized iterative reconstruction method with motion-compensation was proposed to reconstruct the final Result.
The proposed method was evaluated using three groups of simulated ECG-gated angiograms with increasing amount of residual vessel motion. The reconstruction results of the proposed method were quantitatively evaluated using Maximum Mean Overlap (MMO) and Relative Radius Error (RRE) metrics, where larger MMO value and smaller RRE value means a better reconstruction. The MMOs (ECG gated reconstruction vs. motion-compensated reconstruction) for the three groups were (0.94, 0.87, 0.79) vs. (0.96, 0.93, 0.89); The RREs were (7.7, 15.6, 23.3) vs. (4.2, 4.3, 7.1). The reconstruction Result was comparable to that of state-of-the-art method.
We have developed and validated a motion-compensated reconstruction method to handle the residual vessel motion which degrades the ECG gated reconstruction. The method could effectively estimate and compensate the vessel motion, and thus improve the reconstruction quality.